You might want to check out the cowboy action forums before buying. The Beretta Stampede was a Uberti Colt SAA replica with a transfer bar safety (Beretta owns Uberti), and they were not highly thought of. I am not sure if the Stampede had the coil spring or the traditional flat spring.
Personally, my view of the SAA and SAA replica market as of today is this: If money is no object and you want an "authentic, four position hammer, hammer on empty cylinder only" type SAA, Colt is currently a good choice. They have had their ups and downs, but they are, as of 4/27/2013, up.
If you want the authentic four position hammer but money is an object, Uberti in all of its many variations (excluding this Horseman, which I do not know anything about) is a good choice. They generally seem to be well thought of in the CAS community.
If you want an SAA to shoot a lot, and you want to carry six up, and you don't care about the authentic four position hammer, then Ruger's Vaquero is for you.